Non-mechanically fastened TOBI heat shield
A high pressure turbine includes a stator, a rotor, a tangential on-board injector, and a heat shield. The rotor is located downstream of the stator and the tangential on-board injector directs cooling air to the rotor. The heat shield is retained by abutment with the stator and the tangential on-board injector.
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This invention relates generally to gas turbine engines, and more specifically to heat shields for tangential on-board injectors in high pressure turbines.
In a gas turbine engine, air is pressurized in a compressor and mixed with fuel in a combustor for generating hot combustion gases. The combustion gases pass across alternating rows of stationary stator vanes and rotating rotor blades in one or more turbines to produce to both power for the compressor and usable work (e.g. thrust in an aircraft). Gas turbine engine efficiency and energy output increase with turbine operating temperature. Under elevated operating temperatures, turbine vanes and blades are cooled by a flow of air from the compressor. The flow of compressed, cooling air is typically introduced to the turbine through a tangential on-board injector (TOBI).
SUMMARYIn accordance with the present disclosure, a high pressure turbine includes a stator, a rotor, a tangential on-board injector, and a heat shield. The rotor is located downstream of the stator, and the tangential on-board injector directs cooling air to the rotor. The heat shield is retained by abutment with the stator and the tangential on-board injector.
In another embodiment, the stator includes a vane and an inward platform attached to the vane. The rotor includes a blade, an inward root attached to the blade, and an inward disk attached to the root. The tangential on-board injector includes a conduit for directing cooling airflow toward the rotor disk, and an arm extending radially outward from the conduit toward the rotor root. The heat shield is retained by abutment with the platform of the stator and the arm of the tangential on-board injector.
A method for securing a heat shield in a high pressure turbine in accordance with the present disclosure includes inserting the heat shield between a stator and a tangential on-board injector. The method further includes radially retaining the heat shield with the stator, and axially retaining the heat shield with the tangential on-board injector.
As shown in
As described above with respect to
Working Gases (WG) flowing from combustor 18 to HPT 20 are very hot. Although TOBI 36 is not in the direct flow path of Working Gases (WG), OD 44 is adjacent stator 38 therefore, becomes extremely hot. ID 42 of TOBI 36, however, is relatively cool since conduit 46 directs Cooling Air (CA) toward the rotors. Accordingly, TOBI 36 faces a very large thermal gradient between OD 44 and ID 42. Heat shield 40 is attached to OD 44 of TOBI 36 to prevent thermal cracking from thermal mechanical failure. Further, heat shield 40 is designed to help minimize Working Gases (WG) from mixing with (CA), through the use of a flow discourage 78 as shown in
TOBI 36′ and stator 38′ of
TOBI 36′ includes arm 48′, which extends from ID 42′ radially outward and axially downstream to OD 44′. Conduit 46′ is attached to arm 48′ at a location between ID 42′ and OD 44′ and extends axially downstream in order to conduct Cooling Air (CA) to components of HPT 20′. In the depicted embodiment, conduit 46′ imparts tangential motion in Cooling Air (CA) before directing Cooling Air (CA) to disk 66 of rotor 60. Attached to axially downstream and radially inner surfaces of conduit 46′, arm 48′, and OD 44′ are abradable seals 68. Attached to a middle portion of arm 48′, between conduit 46′ and OD 44′, are flanges 70A and 70B. First flange 70A is located upstream on arm 48′ and extends radially outward toward stator 38′. Second flange 70B is located downstream on arm 48′ and extends radially outward toward stator 38′, substantially parallel to first flange 70A. Finger 71 is attached to the downstream edge of OD 44′. From its attachment to OD 44′, finger 71 projects radially outward toward stator 38′. First flange 54A′ of stator 38′ is received between first flange 70A and second flange 70B of TOBI 36′. Second flange 54B′ and foot 67 of stator 38′ cooperate with OD 44′ and finger 71 of TOBI 36′ to trap or “sandwich” heat shield 58 in place.
Heat shield 58 includes body 72, appendage 74, anti-rotation feature 76, and flow discourager 78. Appendage 74 projects axially upstream from its attachment to an upstream portion and radially inward side of body 72. Anti-rotation feature 76 is attached along, and projects radially upstream from, a downstream portion of body 72. Flow discourager 78 is attached to, and projects radially downstream from, the downstream potion of body 72. The structure of heat shield 58 is discussed further below with respect to
When correctly inserted between stator 38′ and TOBI 36′, heat shield 58 is retained solely by abutment with these structures, thereby negating the need a mechanical fastener (shown in
Body 72 is generally shaped like an inverted letter “U” and includes center 80, upstream arm 82, and downstream arm 84. Upstream arm 82 extends radially inward from an upstream side of center 80, and downstream arm 84 extends radially inward from a downstream side of center 80. Upstream arm 82 and downstream arm 84 are substantially parallel to one another on either side of center 80 to form an internal cavity in body 72. Appendage 74 is relatively flat and extends downstream from a radially innermost portion of upstream arm 82. When properly inserted, upper surface 86 of appendage 74 will be in contact second flange 54B′ of stator 38′, and upstream arm 82 of body 72 will be in contact with foot 67 of second flange 54B′. The radially innermost portion of downstream arm 84 includes an angled bottom surface 88. When properly inserted, bottom surface 88 will be in contact with a downstream portion of OD 44′. Anti-rotation feature 76 is generally shaped like a wedge and is attached along an upstream surface of downstream arm 84. The narrowest portion of anti-rotation feature 76 is near center 80 of body 72. As anti-rotation feature 76 extends radially inwardly along upstream arm 84 it also becomes enlarged such that the widest portion is adjacent bottom surface 88. When properly inserted, anti-rotation feature 76 is in contact with an upstream side of finger 71. Additional anti-rotation features and seals can be added onto heat shield 58 to meet requirements of a particular engine without departing from the spirit and scope of the present disclosure. Heat shield 58 is segmented and is intended to be secured, constrained, and held in place solely by abutment between TOBI 36′ and stator 38′ without use of mechanical fasteners.
While the invention has been described with reference to an exemplary embodiment(s), it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment(s) disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.
Claims
1. A high pressure turbine comprising:
- a stator;
- a rotor located downstream of the stator;
- a tangential on-board injector for directing cooling air to the rotor; and
- a heat shield retained by abutment with the stator and the tangential on-board injector;
- wherein the heat shield includes an anti-rotation flange that abuts the tangential on-board injector and provides circumferential constraint for the heat shield.
2. The high pressure turbine of claim 1, wherein a portion of the heat shield is trapped or sandwiched between the stator and the tangential on-board injector.
3. The high pressure turbine of claim 1, wherein the heat shield is radially retained by the stator.
4. The high pressure turbine of claim 3, wherein an upstream portion of the heat shield abuts a radially inward portion of stator.
5. The high pressure turbine of claim 1, wherein the heat shield is axially retained by the tangential on-board injector.
6. The high pressure turbine of claim 5, wherein a downstream portion of the heat shield abuts a radially outer portion of the tangential on-board injector.
7. The high pressure turbine of claim 1, wherein a downstream portion of the heat shield extends into a gap formed between the stator and the rotor to discourage fluid flow within the gap.
8. A high pressure turbine comprising:
- a stator including a vane and an inward platform attached to the vane;
- a rotor located downstream of the stator, the rotor including a blade, an inward root attached to the blade, and an inward disk attached to the root;
- a tangential on-board injector including a conduit for directing cooling airflow toward the rotor disk and an arm extending radially outward from the conduit toward the rotor root; and
- a heat shield retained by abutment with the platform of the stator and the arm of the tangential on-board injector.
9. The high pressure turbine of claim 8, wherein a portion of the heat shield is located between the stator and the tangential on-board injector.
10. The high pressure turbine of claim 8, wherein the stator further comprises:
- a foot extending radially inward from the platform to radially retain the heat shield.
11. The high pressure turbine of claim 8, wherein the tangential on-board injector further comprises:
- a finger extending radially outward from the tangential on-board injector arm to axially retain the heat shield.
12. The high pressure turbine of claim 8, wherein the heat shield includes an anti- rotation flange that abuts the tangential on-board injector and provides circumferential constraint for the heat shield.
13. The high pressure turbine of claim 8, wherein the heat shield extends into a gap formed between the stator and the rotor and at least partially blocks fluid flow within the gap.
14. A method for securing a heat shield in a high pressure turbine, the method comprising:
- inserting the heat shield between a stator and a tangential on-board injector;
- radially retaining the heat shield with the stator;
- axially retaining the heat shield with the tangential on-board injector; and
- circumferentially retaining the heat shield with an anti-rotation feature on the heat shield in abutment with the tangential on-board injector.
15. The method of claim 14, further comprising:
- discouraging flow in a gap between the stator and a downstream rotor with the heat shield.
4526511 | July 2, 1985 | Levine |
4635332 | January 13, 1987 | Cederwall et al. |
4645415 | February 24, 1987 | Hovan et al. |
4822244 | April 18, 1989 | Maier et al. |
5233824 | August 10, 1993 | Clevenger |
5813830 | September 29, 1998 | Smith et al. |
6183193 | February 6, 2001 | Glasspoole et al. |
6276896 | August 21, 2001 | Burge et al. |
6431820 | August 13, 2002 | Beacock et al. |
6468032 | October 22, 2002 | Patel |
6511284 | January 28, 2003 | Darnell et al. |
7114339 | October 3, 2006 | Alvanos et al. |
7174719 | February 13, 2007 | Kim |
7600969 | October 13, 2009 | Frankenstein et al. |
20020076318 | June 20, 2002 | Patel |
20050217277 | October 6, 2005 | Alvanos et al. |
20060037317 | February 23, 2006 | Leavesley |
20070059158 | March 15, 2007 | Alvanos et al. |
20080141677 | June 19, 2008 | Brillert |
20090010751 | January 8, 2009 | McCaffrey et al. |
20090180864 | July 16, 2009 | Alvanos et al. |
20090238683 | September 24, 2009 | Alvanos et al. |
Type: Grant
Filed: Jun 20, 2011
Date of Patent: Dec 2, 2014
Patent Publication Number: 20120321453
Assignee: United Technologies Corporation (Hartford, CT)
Inventor: Ioannis Alvanos (West Springield, MA)
Primary Examiner: Edward Look
Assistant Examiner: William Grigos
Application Number: 13/164,234
International Classification: F04D 31/00 (20060101); F01D 5/08 (20060101); F02C 7/18 (20060101);